DaisyDisk scans any folder (or entire disk), then shows you a circular diagram displaying with segmented rings representing all of your files. Hovering over a segment will show categories of files and folders and their total size. Then you can drill into any part of your drive by clicking a segment to show content details.

You can use the built-in QuickLook preview to see what you might want to get rid of (you can also reveal in Finder to take a closer look). There’s a collection drawer where you can stage files (or entire segments) for trashing. Once you’ve browsed through and collected things you don’t need, one click clears them out.